Oxidation of carbon black over various Pt/MOx/SiC catalysts

Catalytic activities of various Pt/MOx/SiC systems for carbon oxidation under simulated diesel exhaust gas were investigated in temperature-programmed reactions. When Pt/MOx (MOx=TiO2, ZrO2, Al2O3) was loaded onto silicon carbide (SiC), the oxidation activities became higher than those of Pt/MOx alone or other Pt/MOx/SiC systems (MOx=Ta2O5, WO3, Nb2O5, SnO2, SiO2, CeO2, MoO3, V2O5). Among them, Pt/TiO2/SiC exhibited the highest activity. We discuss the activity of MOx=TiO2, ZrO2, and Al2O3 in connection with NO oxidation activity, adsorption of sulfate onto the support, Pt dispersion, and specific surface area of the catalyst. Furthermore, we investigated the catalytic performance of Pt/TiO2/SiC in more detail under isothermal conditions and in a staged arrangement.